1. Field of the Invention
This invention relates to radiation monitors, and more specifically relates to an electromagnetic radiation monitor which may be worn by persons who may be exposed to potentially harmful levels of electromagnetic energy. Even more particularly, this invention relates to a personal electromagnetic radiation monitor for use in the RF (radio frequency) region of the frequency spectrum and which operates substantially independently of polarization.
2. Description of the Prior Art
Attempts have been made to make an electromagnetic radiation monitor which may be worn by a person working in areas where potentially harmful electromagnetic radiation may be present. Early studies, such as those reported by Beischer in his article, Microwave Reflection, Diffraction and Transmission By Man, Department of Naval Aerospace Medical Research Lab, Pensacola, Fla., June, 1973, have shown that scattering from a body may produce errors greater than 2 dB. This scattering becomes more significant where broadband frequency performance and independence of polarization are desired monitor characteristics.
U.S. Pat. No. 5,168,265, which issued to Edward E. Aslan, also the inventor herein, discloses a radiation monitor which is independent of polarization and preferably operable between about 2 GHz and about 18 GHz. The radiation monitor senses the electric field component of the electromagnetic radiation and employs thin film resistive theremocouples for this purpose.
To this date, no practical device being independent of polarization and being responsive to electromagnetic radiation in the RF region, this is, about 0.1 to about 110 MHz, to the knowledge of the inventor, has been successfully marketed.